As higher education institutions enter the intense competition of the rapidly growing global marketplace of online education, the leaders within these institutions are challenged to identify factors critical for developing and for maintaining effective online courses. Computer-mediated communication (CMC) systems are considered critical to successful online courses. Using the Community of Inquiry framework, this study examined the use of CMC systems. Results suggested no significant difference in social presence, cognitive presence or teaching presence between the online students who used only asynchronous CMC systems and those who used a combination of both asynchronous and synchronous CMC systems; however, students' comments suggest that the use of a combination of synchronous and asynchronous CMC systems may increase their sense of community in the online environment. (Contains 1 table.)